NEW YORK (Reuters Health) - In a study of healthy older
adults lifting weights regularly, for 3 months, taking
recommended daily doses of ibuprofen (like that in Advil) or
acetaminophen (like that in Tylenol) led to substantially
greater increases over inactive placebo in quadriceps muscle
mass and strength.

Dr. Chad C. Carroll, a postdoctoral fellow working with Dr.
Todd Trappe in the Human Performance Laboratory at Ball State
University, Muncie, Indiana, reported the study results this
week during the annual meeting of the American Physiological
Society, part of the Experimental Biology 2008 scientific
conference in San Diego.

Taking ibuprofen or acetaminophen regularly during
resistance training seems to induce chances within the muscle
that enhance the metabolic response to resistance exercise,
which promotes additional muscle building and strength gains in
the elderly, the researchers found.

ADVERTISEMENT

During 12 weeks of supervised knee-extensor weight
training, performed three times per week for 15 to 20 minutes,
36 men and women, between 60 and 78 years old, were randomly
assigned to ibuprofen, acetaminophen, or placebo in doses
mimicking what chronic users of these pain relievers were
likely to be taking on a daily basis.

"We used 1200 milligrams a day for ibuprofen and 4000
milligrams per day of acetaminophen, which is the maximum
over-the-counter daily dose," Dr. Trappe explained in an
interview with Reuters Health.

As expected, resistance training alone (placebo group)
increased quadriceps muscle mass and muscle strength. However,
the increases were far greater in the ibuprofen and
acetaminophen groups.

"The muscles of the ibuprofen and acetaminophen users got
40 to 60 percent bigger than the placebo group and their muscle
strength also went up higher than the placebo group," Trappe
said.

Specifically, muscle volume increased 11 percent in the
ibuprofen group and 13 percent in the acetaminophen group,
compared with 9 percent in the placebo group. Muscle strength
increased 30 percent in the ibuprofen group and 28 percent in
the acetaminophen group, compared with 23 percent in the
placebo group.

These finding were somewhat surprising, Trappe said. In a
prior study, his team measured muscle protein synthesis over a
24-hour period and found that ibuprofen and acetaminophen had a
negative impact on muscle by blocking the COX enzyme.

Based on this acute study, "we figured that these drugs
would actually get in the way of muscle building in the elderly
-- the group that seems to benefit the most from doing
resistance exercises," Trappe explained.

The researchers are now examining muscle biopsies taken
from the study subjects before and after the 3-month period of
resistance training to better understand the metabolic
mechanism behind the apparent beneficial effects of ibuprofen
and acetaminophen during weight training.